| 摘要 |
<p>PURPOSE:To facilitate expansion or contraction of an inner boom and make the total device proper sizing by providing the inner boom which expands or contracts by charging or discharging pressure fluid from front or rear side of a fluid tube, and providing rollers closely pressed and contacted with the fluid tube and rotatably movable on the fluid tube, accompanied with lengthwise movement of the inner boom. CONSTITUTION:When pressure fluid 5 is sent from a rear fluid hose 7 to a fluid tube 2, pressure of the pressure fluid is added on rollers 4 and pushes these rollers 4 forward, as the fluid tube 2 is closely pinched with two rollers 4, upper and lower. In this case, the rollers 4 start forward rolling motion on the fluid tube 2. As the rolling motion of the rollers 4 is continued by continuous sending of the pressure fluid 5, an inner boom 3 is expanded forward. Nextly, when the pressure fluid 5 is sent from a front fluid hose 7' to the fluid tube 2 and fluid in the fluid tube 2 is discharged through the rear fluid hose 7, the rollers 4 are rolled backward and the inner boom 3 is retreated in a case 1.</p> |
